This invention relates to a dye image-receiving element for use in a thermal imaging method. More particularly, it relates to an element having pre-printed security indicia and capable of receiving personalized data by a thermal dye diffusion transfer method for the production of identification documents.
In the production of images useful in the field of identification documentation, it is oftentimes desirable to embody into a document (such as an ID card, drivers license, passport or the like) data or indicia representative of the document issuer (e.g., an official seal, or the name or mark of a company or educational institution) and data or indicia representative of the document bearer (e.g., a photographic likeness, name or address). Typically, a pattern, logo or other distinctive marking representative of the document issuer will serve as a means of verifying the authenticity, genuineness or valid issuance of the document. A photographic likeness or other data or indicia personal to the bearer will validate the right of access to certain facilities or the prior authorization to engage in commercial transactions and activities.
Identification documents, such as ID cards, having printed background security patterns, designs or logos and identification data personal to the card bearer have been known and are described, for example, in U.S. Pat. No. 3,758,970, issued Sep. 18, 1973 to M. Annenberg; in Great Britain Pat. No. 1,472,581, issued to G. A. O. Gesellschaft Fur Automation Und Organisation mbH, published Mar. 10, 1976; in International Patent Application PCT/GB82/00150, published Nov. 25, 1982 as Publication No. WO 82/04149; in U.S. Pat. No. 4,653,775, issued Mar. 31, 1987 to T. Raphael, et al.; in U.S. Pat. No. 4,738,949, issued Apr. 19, 1988 to G. S. Sethi, et al.; and in U.S. Pat. No. 5,261,987, issued Nov. 16 1993 to J. W. Luening, et al.
In the aforementioned Great Britain Patent No. 1,427,581, a pre-printed photographic paper having a security-technical printed design is exposed to light, developed and fixed to provide a paper bearing the preprinted design and photographically recorded information in the form of pictures and/or data. In the aforementioned U.S. Pat. No. 4,653,775, there is described an image-receiving element (having a pre-printed security pattern) for receipt of personalized data by a photographic dye diffusion transfer ("instant") method. According to the teachings of the aforementioned International application (Patent Publication No. WO 82/04149), a paper carrying a security print or design is used as a paper base over which an image is printed in ink and/or toner in the form of a facsimile-printed graphic image.
The advent of commercial apparatus (printers) for producing dye images by thermal transfer has made relatively commonplace the production of color prints from electronic data acquired by a video camera. In general, this is accomplished by the acquisition of digital image information (electronic signals) representative of the red, green and blue content of an original, using color filters or other known means. These signals are then utilized by a printer having a plurality of small heating elements (e.g., pins) for imagewise heating of each of a series of donor sheets (respectively, carrying sublimable cyan, magenta and yellow dye). The donor sheets are brought into contact with an image-receiving element which has a layer for receiving the dyes transferred imagewise from the donor sheets. Thermal dye transfer methods as aforesaid are known and described, for example, in U.S. Pat. No. 4,621,271, issued Nov. 4, 1986 to S. Brownstein and U.S. Pat. No. 5,024,989, issued Jun. 18, 1991 to Y. H. Chiang, et al.
The application of thermal dye transfer methods to the production of identification (ID) cards, including ID cards carrying background security printing and personalized data in dye transferred by thermal diffusion processing is described in the aforementioned U.S. Pat. Nos. 4,738,949 and 5,261,987. It will be appreciated that the security of an identification document will be dependent upon the particular structure and properties of the layers and the ease with which a successful intrusion can be accomplished. In the case, for example, of the dye image-receiving element of the aforementioned U.S. Pat. No. 4,738,949, there is produced a monolithic ID card, by which is meant that the background information and the photograph or other personalized information are contained in the same layer. It is indicated in the patent (col. 2, lines 63-66) that, in this way, tampering with the photograph will destroy the background information and forgeries can be prevented.
In U.S. Pat. No. 5,261,987, reference is made to the ID cards of the aforesaid U.S. Pat. No. 4,738,949 and to the lamination of a transparent laminate (employing adhesive) onto the image-bearing surface. It is indicated that attempts to delaminate or peel apart the double composite laminate caused the thermally-transferred dye image to be lifted off the polycarbonate dye-receiver layer by virtue of the strong adhesion provided by the adhesive. It is further disclosed that, in the case of the lamination between polyvinyl chloride sheets of a support sheet carrying a polycarbonate surface having personalized and background information thereon, the incorporation of the support sheet into the ID card renders the card susceptible to being delaminated and altered. There is, thus, disclosed in U.S. Pat. No. 5,261,987 a method of increasing tamper resistance whereby personalized information is printed (by thermal dye transfer printing) onto the exposed surface of a polycarbonate receiver sheet and the polycarbonate receiving layer of the receiver element is then adhered and transferred to a cardstock material pre-printed with background information.